Datacenters that house large amounts of computing equipment are critical for modern business and commerce systems. Applications such as banking, e-commerce, cloud computing, cloud storage, video sharing, and social media all rely on datacenters to implement their respective services. The reliability of such datacenters is a function of the reliability of the electric power sources used by these datacenters.
According to recent indications, over 70 percent of datacenters suffer an unplanned outage of some duration within a 24-month period. The most common cause of a power outage is inclement weather. However, power outages can also occur from simple equipment failure or an accidental severing of a buried power line. No matter what the reason is, an unplanned outage can cost a company a significant amount of money, especially if the affected organization's revenues are dependent upon Internet sales/access. It has been estimated that the average U.S. datacenter loses approximately $138,000 for one hour of datacenter downtime per year. Thus, it is desirable to avoid downtime as much as possible. Due to the high costs of a datacenter outage, a Service Level Agreement (SLA) is often used between a datacenter and its clients to establish a level of various service attributes. Service attributes can include responsiveness, monitoring, and reliability, among others. For the attribute of reliability, power supplied to the datacenter plays a key role in the uptime of a datacenter.
With datacenters, also known as “server farms,” there can be hundreds or even thousands of racks, each housing interconnected devices. The devices on the racks typically provide functionality, including the storage, processing, and retrieval of data. Given the power requirements demanded by the rack-mounted devices, reliable and efficient power delivery is crucial for the organizations using the datacenters to successfully operate. In some cases, the reliability and availability requirements placed on the devices powering the datacenter infrastructure must meet or exceed predetermined statutory requirements, as is the case for financial institutions.
Regardless of the type of institution, various infrastructure requirements must be met in order to address the important issues of availability, reliability, job load, and other organizational requirements of datacenters. For example, the issue of effectively cooling a datacenter (i.e. the removal of excess heat) is a critical issue which must be addressed to ensure stable and reliable operation of the datacenter. The cooling of modern datacenters is so important that it can directly impact the layout and architectural design of the center. Another significant datacenter design consideration involves providing sufficient power to the datacenter. Particularly in the case of high-reliability datacenters such as those used for e-commerce, banking, airline reservations, video distribution, and the like, power can be provided by more than one power grid, while for other datacenters, power can be provided by a combination of a power grid and locally generated power. For all applications, prevention of datacenter downtime, and proper redundancy for a given Service Level Agreement are important aspects of successful datacenter operation.